Skip to main content
Download PDF

Effect of placenta location detected by ultrasound on the severity of placenta accreta spectrum in patients with placenta previa and placenta accreta spectrum

BMC Pregnancy and Childbirth volume 23, Article number: 406 (2023) Cite this article

Abstract

Background

To evaluate the effect of placental location on the severity of placenta accreta spectrum (PAS).

Methods

We analyzed 390 patients with placenta previa combined with placenta accreta spectrum who underwent cesarean section between January 1, 2014 and December 30, 2020 in the electronic case database of the Second Hospital of Hebei Medical University. According to the position of the placenta, 390 placentas were divided into the posterior group (n = 89), the anterior group (n = 60) and the non-central group (n = 241).

Results

The history of cesarean delivery rates in the anterior group (91.67%) and the non-central group (85.71%) were statistically different from the posterior group (63.74%)(P < 0.001). Univariate logistic regression results showed that employment, urban living, gestational age, complete placenta previa, fetal presentation shoulder, gravidity, cesarean section and vaginal delivery were all predictors for the severity of placenta accreta (P < 0.05). The anterior group (P = 0.001, OR = 4.13, 95%CI: 1.84–9.24) and the non-central group (P = 0.001, OR = 2.90, 95%CI: 1.55–5.45) had a higher incidence of invasive accreta placentation than the posterior group, and were independent risk factors for invasive accreta placentation.

Conclusion

Compared with posterior placenta, anterior and non-central placenta are independent risk factors for invasive PAS in patients with placenta previa, during which we should be more cautious in treatment.

Peer Review reports

Background

Placenta accreta spectrum (PAS) is a group of diseases in which placental tissue invades the myometrium. It is one of the most critical and severe obstetrics diseases, resulting in postpartum bleeding, secondary infection, multiple organ failure, perinatal hysterectomy, pelvic organ damage and other complications, even maternal and newborn deaths [1]. The incidence of PAS is increasing year by year [2]. A recent systematic review and meta-analysis of 23 cohort studies involving 350,939 women in mainland China found that the incidence of PAS increased from 0.03% in 1970–1979 to 0.48% in 2010–2016 [3]. PAS has many risk factors. The incidence of PAS increases with the increase of cesarean section history [4]. In addition, studies have found that other risk factors for placenta accreta include uterine surgery, in vitro fertilization, multiple births, and maternal age [5].

A unified appropriate diagnostic criterion for PAS is an important prerequisite for standardized clinical diagnosis and treatment and follow-up research. According to the definition, pathological diagnosis is the most objective and accurate, and the pathological grading criteria of PAS are constantly updated and verified [6, 7]. It is proposed that cases with hysterectomy and placenta in situ retention should be carefully examined and analyzed according to gross or microscopic manifestations. However, with the continuous improvement of clinical management of PAS, the number of hysterectomy is relatively reduced. In 2019, the relevant guidelines [8] were issued by the new International Federation of Gynecology and Obstetrics (FIGO) to define the intraoperative clinical grading criteria. At present, both intraoperative diagnosis and pathological diagnosis can be used as the diagnostic criteria for PAS. Invasive PAS refers to cases graded as grade 2 or higher, and non-invasive refers to cases graded as grade 1.

In recent years, abnormal placentation, especially placenta previa combined with PAS has become a hot research topic in obstetrics field [9]. There are few studies on the effect of placenta location on the severity of PAS in the patients with placenta previa. Therefore in this study, we aimed to evaluate the effect of placental location on the severity of PAS in the patients with placenta previa and PAS.

Methods

We retrospectively analyzed 390 patients with placenta previa combined with placenta accreta who underwent cesarean section in the obstetrics department between January 1, 2014 and December 30, 2020 in the electronic case database of the Second Hospital of Hebei Medical University. Exclusion criteria were patients (1) with pregnancy complicates such as diabetes and hypertension; (2) with gestational age < 28 weeks and > 42 weeks; (3) with serious medical and surgical complications, such as malignant tumor; (4) with data loss. This study was approved by the Ethics Committee of the Second Hospital of Hebei Medical University (No. 2021–2178), and informed consent was obtained from each participant.

PAS was confirmed by intraoperative diagnosis or pathological diagnosis in all cases in this study. According to the FIGO guidelines, placenta accreta, placenta increta and placenta percreta are classified. Placenta increta and placenta percreta are collectively referred to as invasive accreta placentation according to their histological and clinical definitions [8]. Therefore the PAS was divided into two groups: adherent accreta placentation and invasive accreta placentation.

Clinical diagnostic criteria for adherent accreta placentation: Visually, there is no obvious distension of the uterus on the placental bed (placental bulge), no placental tissue invading the surface of the uterus, and no or minimal neovascularity. Manual removal of the placenta can cause heavy bleeding from the placenta accreta site requiring mechanical or surgical procedures. Clinical diagnostic criteria for invasive accreta placentation: Macroscopic abnormalities of the placenta bed are observed including bluish/purple colouring and distension (placental bulge). Gentle cord traction results in the uterus being pulled inwards without separation of the placenta (the dimple sign) [8].

All patients underwent two-dimensional ultrasound and color Doppler ultrasound examination before delivery. In present study, Ultrasound was done by ultrasound system, using the curvilinear transducer. The lower uterine segment is evaluated using the highest-frequency transducer that can produce an adequate image. Transabdominal ultrasound is performed with the patient's bladder full. The patients were positioned in a supine state on a chair, and the probe was applied with couplant before being placed on the patient's abdomen for exploration. Multi-section plain scanning of longitudinal and transverse sections of the abdomen was conducted using the GEVOLUSONE10 two-dimensional ultrasound to observe the internal echo of the placenta, the relationship between the placenta and the uterine muscle wall, the boundary state of the uterine myometrium, the relationship between the uterus and the bladder, and the smoothness of the bladder wall. Following this, the GEVOLUSONE10 color Doppler ultrasound was used to observe the blood flow within the placenta, between the uterine wall of the placenta, and between the uterine wall and the bladder, with key exploration parameters being recorded.

Placental location diagnosis: According to the position of the placenta examined by ultrasound in the week before surgery, 390 placentas were divided into three groups: the posterior group (n = 89), the anterior group (n = 60) and the non-central group (n = 241). Anterior wall placenta: More than 50% of the placental tissue is attached to the anterior wall. Posterior wall placenta: More than 50% of the placental tissue is attached to the posterior wall. Non-central placenta: cases other than anterior and posterior placenta. The risk of complications with the placenta on the posterior wall is lower than elsewhere, so the posterior wall group was selected as the control group [10].

Statistical analysis

The statistical software Empower Stats (http://www.empowerstats.com, X&Y Solutions, Inc., Boston, MA) was used for statistical analysis. Continuous variables were expressed as mean ± standard deviation (SD), and differences between groups were compared by ANOVA. Categorical variables were represented by number (percentage), and differences between groups were compared by χ2 test. The p-value is obtained by Kruskal Wallis rank sum test for variables of skewed distribution. If the counting variable has a theoretical number < 10, the p-value is obtained by Fisher's exact probability test. Indicators and effect values were expressed with 95% confidence intervals. Univariate and multivariate logistic regression were used to explore the effect of placenta position on the degree of placenta accreta. In the basic model or the complete model, the covariates that had an impact on > 10% of the regression coefficient of X or regression coefficient P < 0.1 of Y were identified as confounders and adjusted in the multiple regression model. Two-tailed probability value of P < 0.05 was considered as statistically significant.

Results

Baseline data

As shown in Table 1, the factors affecting placenta attachment position include gestational age, gravidity, parity, number of vaginal delivery, type of placenta previa and number of cesarean delivery among patients with placenta previa combined with PAS. The results showed that the history of cesarean delivery rates in the posterior, anterior and non-central groups were 63.74%, 91.67% and 85.71%, respectively, and the anterior and the non-central groups are statistically different from the posterior group respectively (P < 0.001). Age, BMI, region, occupation, bleeding during pregnancy, emergency, multiple births, and fetal position had no effect on placenta position.

Table 1 Baseline data in three groups
Full size table

According to the severity of placenta accreta, patients were divided into two groups: adherent accreta placentation group (n = 132) and invasive accreta placentation group (n = 258). As shown in Table 2, the gestational age, region, occupation, gravidity, parity, number of vaginal delivery, the type of placenta previa, history of cesarean delivery, fetal presentation, and placental location were significantly different in adherent accreta placentation and Invasive accreta placentation groups (P < 0.05).

Table 2 Comparison of basic data between two groups of people with different degree of PAS
Full size table

The factors affecting the placenta attachment location in Table 1 and factors having an impact on the severity of placenta accreta indicated by previous studies were all subject to single-factor logistic regression for the degree of placenta accreta, and the positive results were shown in Table 3. Univariate logistic regression analysis was performed on the severity of PAS based on various influencing factors. The results showed that employment, urban living, gestational age, complete placenta previa, fetal presentation shoulder, gravidity, cesarean section and vaginal delivery were all predictors for the severity of placenta accreta (P < 0.05).

Table 3 Factors influencing the severity of placenta implantation in patients with placenta previa and PAS
Full size table

As shown in Table 4, multiple logistic regression analysis was performed to analyze the influence of placental position on the severity of placenta accreta. When covariates were introduced into the base model or in the complete model, adjust I removed the covariates when their impact on the regression coefficient of X was > 10%. Adjust II eliminated the covariates, when their impact on the regression coefficient of X > 10% or the regression coefficient of Y P value < 0.1. The results showed that the anterior group (P = 0.001, OR = 4.13, 95%CI: 1.84–9.24) and the non-central group (P = 0.001, OR = 2.90, 95%CI: 1.55–5.45) had a higher incidence of invasive accreta placentation than the posterior group, and were independent risk factors for invasive accreta placentation. The curve fitting between placenta position and the severity of PAS was carried out, as shown in Fig. 1. It can be seen that placenta located on the anterior wall has a greater impact on the severity of PAS.

Table 4 Multivariate logistic regression analysis of the effect of placenta position on the severity of PAS in patients with placenta previa and PAS
Full size table
Fig. 1
figure 1

The fitting curve of placenta position and the severity of PAS in patients with placenta previa and PAS. The X-axis represents placental location. 1 is the posterior group, 3 is the anterior group, and 4 is the non-central 4 group. The Y-axis represents the incidence and 95% confidence interval of invasive placental implantation

Full size image

Comparison of maternal and infant outcomes among the three groups was shown in Table 5. There were significant differences in operation time, intraoperative blood loss, blood transfusion, fetal weight and postoperative hospital stays among the three groups (P<0.05).

Table 5 Maternal and infant outcomes in 3 groups
Full size table

Univariate regression analysis of maternal and infant outcomes between the anterior group and non-central group was shown in Table 6, and it was found that the intraoperative blood loss, transfusion and postoperative hospital stay in the anterior group and the non-central group were higher than the posterior group (P < 0.05), fetal weight in the non-central group was lower than that in the posterior group (β = -194.1 95%CI: -325.9,-62.2, P = 0.004), and maternal complications in the non-central group was higher than the posterior group (OR = 2.3, 95%CI:1.1,4.6, P = 0.028).

Table 6 Univariate analysis of maternal and infant outcomes
Full size table

Discussion

In this study, we found that placenta placement in the anterior and non-central wall has a greater impact on the severity of PAS than the posterior wall, after adjusted for confounding factors including region, parity, cesarean section, and placenta previa type. The risk of invasive accreta placentation for anterior placenta was 3.13 times higher than posterior placenta, and the risk of invasive accreta placentation for non-central placenta was 1.90 times higher than posterior placenta. Severe PAS indicated an increased risk of adverse maternal and infant outcomes including massive bleeding and hysterectomy [11, 12].

Cases of placenta previa with PAS were selected in this study. In the anterior group, 91.67% had a history of cesarean section. When the placenta is located on the anterior wall and in a low position, it is likely to cover the scar of the uterus. Study found that in the incision healing process of patients with cesarean section, more than 1/2 had the wedge-shaped healing defects [13]. The endometrium is damaged, and growed poor at the incision, and the muscularis is weak after cesarean section. Once the villi are implanted here, the bottom decidua is poorly formed, and trophoblast cells can directly invade the myometrium. The villi adhered to the myometrium, implanted and even penetrated the uterine wall [14]. The invasive PAS may occur as a result of partial or complete rupture of the uterine scar, resulting in deeper infiltration of villous trophoblast cells [15]. Therefore cesarean sections are also important factors in the severity of placental implantation. However, after adjusting the effect of cesarean section, the anterior placenta was still associated with invasive PAS in this study. This indicated that there were other reasons that affect the proliferation of placental villus and trophoblast cells, which have also been confirmed in a previous study [16], and the possible mechanism still needs to be further explored.

Jing L et al. found that there is an increased risk of adverse pregnancy outcomes and postpartum haemorrhagia in patients with placenta previa, when the placenta is located on the anterior wall [17]. Morgan E A et al. found that PAS with posterior placental location is associated with delayed diagnosis, surgical complications, assisted reproductive technology, and lower numbers of prior cesarean deliveries relative to anterior location [18]. Given that severe PAS indicated an increased risk of adverse maternal and infant outcomes [11, 12], these findings are similar to ours.

In addition, different parts of the uterus have different shapes and blood supply. The anatomy structure of other parts of the uterus is not as flat as the anterior and posterior walls of the uterus, which is not conducive to placenta attachment [19]. In order to absorb more nutrients to supply the fetus, the placenta will penetrate further into the myometrium. These may be the reasons why the non-central group had more severe PAS. In addition, complete placenta previa was observed in 97.55% of the non-central group. The whole placental tissue of complete placenta previa completely covered the entire os uteri, occupying a large area of the lower uterine segment, while the muscle layer of the lower uterine segment in pregnancy was thin [20]. On this basis, because the placenta has abundant blood transport, it is easy to have adverse pregnancy outcomes such as placenta implantation.

The history of cesarean section and placenta previa are independent risk factors for PAS, and the incidence of PAS will increase with the number of previous cesarean sections [21]. Meanwhile, the incidence of PAS in pregnant women with placenta previa increased compared with those without placenta previa [22]. This is also similar to the results of our study, indicating that cesarean section and placenta previa type were the major confounders of placenta position on the severity of placenta accreta. In addition, in this study, employment, urban living, gestational age, complete placenta previa, fetal presentation shoulder, gravidity, and vaginal delivery were all correlated with the severity of PAS, which is consistent with the results of previous studies [21, 23, 24]. The effect of low gestational age on the severity of PAS may be due to the early intervention of severe placental implantation. In addition, previous study found that in vitro fertilization, multiple pregnancy and maternal age are also risk factors for PAS [25], however this is inconsistent with this study, which may be related to the low number of positive cases in each group.

Clinical prediction model can be regarded as a quantitative tool for medical risk assessment and patient benefit assessment, as well as a means of precision medicine and individualized medicine, which can provide more intuitive and rational information for both doctors and patients. Evaluating patients with PAS is of paramount importance, but identifying the many risk factors involved can be challenging. Recent studies have developed clinical prediction models based on clinical data, highlighting the potential for timely risk stratification of the target population [26, 27]. A prospective cohort study constructed a model including four key variables (loss of clear zone, abnormal placental lacunae, placental bulge and bladder wall interruption) was shown to reliably predict presence and severity of PAS. This is the first time this has been demonstrated using the recently codified definitions of the US signs and disease definitions [28]. These findings highlight the need for large prospective studies aimed at exploring whether the clinical prediction model for PAS can improve the prenatal diagnostic accuracy and surgical outcome.

There were some limitations of this study. This study lacks complete, detailed and effective information on placenta location. Except for placenta previa, there is no official classification of placenta location. In our study, it might be inaccurate to divide the placenta into three positions based only on transabdominal ultrasound examination, without combining transvaginal ultrasound examination. In addition, there were no patients without PAS were included as a control group. In the future, we will further combine risk factors to establish a prenatal prediction model for the degree of placenta accreta, so as to improve the accuracy of prenatal diagnosis of placenta accreta.

Conclusions

In conclusion, we found that the anterior placenta and the non-central placenta are independent risk factors for invasive PAS in patients with placenta previa, during which we should be more cautious in treatment. Prenatal diagnosis of placental implantation degree is a complex problem. Next, we will collect more data and create a clinical prediction model for prenatal diagnosis of placental implantation degree, providing a basis for clinical treatment.

Availability of data and materials

The datasets generated during and analyzed during the current study are not publicly available, but are available from the corresponding author on reasonable request.

References

  1. Silver RM, Branch DW. Placenta Accreta Spectrum. N Engl J Med. 2018;378:1529–36.

    Article  PubMed  Google Scholar 

  2. Committee on Obstetric Practice. Committee opinion no. 529: placenta accreta. Obstet Gynecol. 2012;120:207–11.

  3. Fan D, Li S, Wu S, Wang W, Ye S, Xia Q, et al. Prevalence of abnormally invasive placenta among deliveries in mainland China: A PRISMA-compliant Systematic Review and Meta-analysis. Medicine (Baltimore). 2017;96:e6636.

    Article  PubMed  Google Scholar 

  4. Eshkoli T, Weintraub AY, Sergienko R, Sheiner E. Placenta accreta: risk factors, perinatal outcomes, and consequences for subsequent births. Am J Obstet Gynecol. 2013;208:219.e211-217.

    Article  Google Scholar 

  5. Bowman ZS, Eller AG, Bardsley TR, Greene T, Varner MW, Silver RM. Risk factors for placenta accreta: a large prospective cohort. Am J Perinatol. 2014;31:799–804.

    PubMed  Google Scholar 

  6. Hecht JL, Baergen R, Ernst LM, Katzman PJ, Jacques SM, Jauniaux E, et al. Classification and reporting guidelines for the pathology diagnosis of placenta accreta spectrum (PAS) disorders: recommendations from an expert panel. Mod Pathol. 2020;33:2382–96.

    Article  PubMed  Google Scholar 

  7. Salmanian B, Shainker SA, Hecht JL, Modest AM, Castro EC, Seaman RD, et al. The Society for Pediatric Pathology Task Force grading system for placenta accreta spectrum and its correlation with clinical outcomes. Am J Obstet Gynecol. 2022;226:720.e721-720.e726.

    Google Scholar 

  8. Jauniaux E, Ayres-de-Campos D, Langhoff-Roos J, Fox KA, Collins S. FIGO classification for the clinical diagnosis of placenta accreta spectrum disorders. Int J Gynaecol Obstet. 2019;146:20–4.

    Article  PubMed  Google Scholar 

  9. Machado LS. Emergency peripartum hysterectomy: Incidence, indications, risk factors and outcome. N Am J Med Sci. 2011;3:358–61.

    Article  PubMed  PubMed Central  Google Scholar 

  10. Torricelli M, Vannuccini S, Moncini I, Cannoni A, Voltolini C, Conti N, et al. Anterior placental location influences onset and progress of labor and postpartum outcome. Placenta. 2015;36:463–6.

    Article  CAS  PubMed  Google Scholar 

  11. Marcellin L, Delorme P, Bonnet MP, Grange G, Kayem G, Tsatsaris V, et al. Placenta percreta is associated with more frequent severe maternal morbidity than placenta accreta. Am J Obstet Gynecol. 2018;219:193.e191-193.e199.

    Article  Google Scholar 

  12. Seet EL, Kay HH, Wu S, Terplan M. Placenta accreta: depth of invasion and neonatal outcomes. J Matern Fetal Neonatal Med. 2012;25:2042–5.

    Article  PubMed  Google Scholar 

  13. Timor-Tritsch IE, Monteagudo A, Calì G, D’Antonio F, Kaelin AA. Cesarean Scar Pregnancy: Diagnosis and Pathogenesis. Obstet Gynecol Clin North Am. 2019;46:797–811.

    Article  PubMed  Google Scholar 

  14. Fitzpatrick KE, Sellers S, Spark P, Kurinczuk JJ, Brocklehurst P, Knight M. The management and outcomes of placenta accreta, increta, and percreta in the UK: a population-based descriptive study. BJOG. 2014;121:62–71.

  15. Liu X, Wang Y, Wu Y, Zeng J, Yuan X, Tong C, et al. What we know about placenta accreta spectrum (PAS). Eur J Obstet Gynecol Reprod Biol. 2021;259:81–9.

    Article  PubMed  Google Scholar 

  16. Granfors M, Stephansson O, Endler M, Jonsson M, Sandström A, Wikström AK. Placental location and pregnancy outcomes in nulliparous women: A population-based cohort study. Acta Obstet Gynecol Scand. 2019;98:988–96.

    Article  PubMed  Google Scholar 

  17. Jing L, Wei G, Mengfan S, Yanyan H. Effect of site of placentation on pregnancy outcomes in patients with placenta previa. PLoS ONE. 2018;13:e0200252.

    Article  PubMed  PubMed Central  Google Scholar 

  18. Morgan EA, Sidebottom A, Vacquier M, Wunderlich W, Loichinger M. The effect of placental location in cases of placenta accreta spectrum. Am J Obstet Gynecol. 2019;221:357.e351-357.e355.

    Article  Google Scholar 

  19. Kofinas AD, Penry M, Greiss FC Jr, Meis PJ, Nelson LH. The effect of placental location on uterine artery flow velocity waveforms. Am J Obstet Gynecol. 1988;159:1504–8.

    Article  CAS  PubMed  Google Scholar 

  20. Carusi DA. The Placenta Accreta Spectrum: Epidemiology and Risk Factors. Clin Obstet Gynecol. 2018;61:733–42.

    Article  PubMed  Google Scholar 

  21. Zhang H, Dou R, Lin L, Wang Q, Huang B, Zhao X, et al. Analysis of risk factors and ultrasonic imaging manifestations affecting placenta implantation degree. Chin J Obestet Gynecol, 2019;54:27–32.

  22. Kyozuka H, Yamaguchi A, Suzuki D, Fujimori K, Hosoya M, Yasumura S, et al. Risk factors for placenta accreta spectrum: findings from the Japan environment and Children’s study. BMC Pregnancy Childbirth. 2019;19:447.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. Nageotte MP. Always be vigilant for placenta accreta. Am J Obstet Gynecol. 2014;211:87–8.

    Article  PubMed  Google Scholar 

  24. Silver RM, Fox KA, Barton JR, Abuhamad AZ, Simhan H, Huls CK, et al. Center of excellence for placenta accreta. Am J Obstet Gynecol. 2015;212:561–8.

    Article  PubMed  Google Scholar 

  25. Jauniaux E, Chantraine F, Silver RM, Langhoff-Roos J. FIGO consensus guidelines on placenta accreta spectrum disorders: Epidemiology. Int J Gynaecol Obstet. 2018;140:265–73.

    Article  PubMed  Google Scholar 

  26. Hu Y, Chen W, Kong C, Lin G, Li X, Zhou Z, et al. Prediction of placenta accreta spectrum with nomogram combining radiomic and clinical factors: A novel developed and validated integrative model. Int J Gynaecol Obstet. 2023. https://doi.org/10.1002/ijgo.14710.

  27. Cali G, I Timor-Tritsch, Forlani F, J Palacios-Jaraquemada, F D'Antonio, Andrea K, et al. Integration of first‐trimester assessment in the ultrasound staging of placenta accreta spectrum disorders. Ultrasound Obstet Gynecol. 2020;55:450–9.

  28. Sargent W, Gerry S, Collins SL. A Risk-Prediction Model for Placenta Accreta Spectrum Severity From Standardized Ultrasound Markers. Ultrasound Med Biol. 2023;49:512–9.

    Article  PubMed  Google Scholar 

Download references

Acknowledgements

Not applicable.

Funding

Funding information is not applicable.

Author information

Authors and Affiliations

  1. Department of Physical Examination Center, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China

    Hong Liu, Baolian Zhang & Jing Han

  2. Department of Gynecology and Obstetrics, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China

    Wenli Wang, Xianghua Huang & He Zhu

  3. Department of Ultrasound in Obstetrics and Gynecology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China

    Haiyan Li

  4. Department of Quality Control, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China

    Jia Wang

Authors
  1. Hong Liu
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Baolian Zhang
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Wenli Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Haiyan Li
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Xianghua Huang
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Jia Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Jing Han
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. He Zhu
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

(I) Conception and design of study: Hong Liu; Baolian Zhang; (II) Provision of study materials: Wenli Wang; Haiyan Li; (III) Collection and assembly of data: Hong Liu; Baolian Zhang; Wenli Wang; Haiyan Li; Xianghua Huang; Jia Wang; Jing Han; He Zhu; (IV) Data analysis and interpretation: Wenli Wang; Haiyan Li; (V) Manuscript writing: Hong Liu; Baolian Zhang; (VI) Final approval of manuscript: All authors.

Corresponding author

Correspondence to Xianghua Huang.

Ethics declarations

Ethics approval and consent to participate

The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The trial was conducted in accordance with the Declaration of Helsinki (as revised in 2013). This study was approved by the Ethics Committee of the Second Hospital of Hebei Medical University (No. 2021–2178). Informed consent was taken from all individual participants.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Liu, H., Zhang, B., Wang, W. et al. Effect of placenta location detected by ultrasound on the severity of placenta accreta spectrum in patients with placenta previa and placenta accreta spectrum. BMC Pregnancy Childbirth 23, 406 (2023). https://doi.org/10.1186/s12884-023-05736-w

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1186/s12884-023-05736-w

Keyword

BMC Pregnancy and Childbirth

ISSN: 1471-2393

Contact us